Ok I've played this and here's my review:
objective: kill 500 enemies before the time is up
time given for mission: 20 minutes
rewards: I honestly don't know as I haven't cleared it yet..... (soon my precious, soon. *gollum**gollum*)
Well the lack of movement space makes it a "last stand" mission also
I'd would be a nice idea to remove the enemy drops, as the insane amount of dropped items
plus the incoming mobs make it very laggy to move, speak, or change weapons
a great place to level up or use the lame D or excal